The goal of the Administrative/Animal Core is to provide support for each of the projects funded in the Program Project. The Administrative/Animal Core has multiple aims: 1. The Core will provide administrative assistance in record keeping, personnel management, library services, and preparation of manuscripts. This includes organizing weekly meetings of the Project Leaders, organizing seminars relevant to the goals of the program project, and facilitating interactions with senior consultants to the program project. One consultant will be invited each year to review progress on the goals of the PPG and provide advice on future directions. 2. The Core will procure and maintain animals used by program investigators and meet all AAALAC and institutional standards for animal care in the satellite facilities. The Core will maintain a breeding colony of dw/dw and dw/+ Lewis rats and provide offspring (dw/+, dwldw +/- GH, dw/dw+saline) to be used for the model of adult-onset growth hormone deficiency. The Core personnel will assess basic parameters of aging animals (general health and body weight), monitor sentinel and experimental animals for the presence of disease and provide these data to project investigators. Finally, Core personnel will be responsible for conducting peripheral cardiovascular measurements using telemetry and conducting behavioral analyses on animals as requested by the program project investigators. 3. The Core will conduct studies of alterations in gene expression using large scale DNA macroarrays and smaller custom arrays for genes determined to be of interest to project investigators. 4. The Core will provide support in the design, data management, and statistical analyses of within project and between project results with the assistance of Dr. Walter Ambrosius, Statistician for the program. The Administrative/Animal Core is an essential aspect of the Program Project ensuring effective management of limited resources, smooth interactions between projects and the use of animal models that have been validated for studies of the biology of aging. The availability of the Administrative/Animal Core has been a key part of the success of our program to date and will perform responsibilities that are essential to meet the scientific objectives of the program project in the next funding period.